The present invention relates generally to recording systems in common control telephone equipment and is more particularly directed to an automatic message accounting system for toll communications.
Toll ticketing or providing a hard copy record of the rate and time a subscriber uses telephone system equipment has been a feature in telephone systems almost since their conception.
In older systems, an operator was required to handwrite toll tickets for the subscribers making toll calls. In more recent systems with the advent of direct distance dialing (DDD), the concept of automatic message accounting or ticketing without operator assistance has been developed.
Automatic message accounting systems are a necessity for the common control telephone systems of today. The speed at which such telephone systems operate and the number of subscribers they may handle simultaneously must be matched by an accounting system of similar speed and capability. Also, modern automatic message accounting systems should have the capability of toll charging all unassisted dialed calls from a subscriber. These calls generally have the designation of sent paid, station-to-station (SPSS) terminations and are usually accessed by the use of a 1+ called number code. The SPSS or 1+ call may be one of two types, a local or a tributary connection.
The local call requiring local automatic message accounting (LAMA) is made by a subscriber, serviced by the exchange with the ticketing equipment, to another subscriber at an external exchange. However, it is generally inefficient to equip every exchange with ticketing equipment and a central exchange, usually a larger class office, is selected to perform centralized automatic message accounting (CAMA) for a plurality of tributary office exchanges. Therefore, it is a general requirement that such CAMA ticketing equipment provide a large traffic handling capability with respect to both speed and size. The tributary connection through the ticketing exchange may be made either to a local subscriber at the ticketing exchange or to another tributary office. It would also be advantageous to ticket both LAMA and CAMA calls with common ticketing equipment.
Many CAMA and LAMA systems have automatic number identification (ANI) for directing the calling number into the accounting system. There are instances, however, where SPSS calls are made from multiparty lines or exchanges without ANI or instances where a request for the ANI results in an equipment failure. Provision should be made in modern AMA systems for handling toll ticketing of these calls with the same facility as the ANI terminations.
One solution for providing a modern automatic message accounting system has been proposed in U.S. Pat. No. 3,829,617, issued to Caithamer, et al. The proposal includes the insertion of service junctors into the path between an originating office and a toll switching exchange. The junctors are connected to a plurality of receivers and information sent to the toll exchange is intercepted and recorded and then resent by sending circuits. The primary problem with such a system is that the common control of the toll exchange must wait for the information until the AMA system has recorded and resent it. This system also lacks facilities for providing efficient LAMA terminations or calls depending on ONI.
Another AMA system is described in U.S. Pat. No. 3,601,542 issued to Stewart, et al. In this system a plurality of recording trunks are used at the toll switching office to store information in a dynamic or recirculating memory. Although this system advantageously provides the recorder memory on a time-shared basis to the common control for information storage, it has the disadvantage of increasing the connection time of a toll call by requiring a register-sender to outpulse the toll information to the recorder through the recording trunks.
Accordingly it is an object of the present invention to provide a high capacity AMA system with increased speed.
It is a further object of the invention to provide an AMA system with combined LAMA and CAMA capability.
It is another object of the invention to provide for ticketing calls of a 1+ nature requiring ONI or incurring an ANI failure.